1 files changed, 19 insertions, 17 deletions

diff --git a/sound/drivers/aloop.c b/sound/drivers/aloop.c
index 0fe6d64ff840..1904046686e2 100644
--- a/sound/drivers/aloop.c
+++ b/sound/drivers/aloop.c
@@ -120,7 +120,6 @@ struct loopback_pcm {
         unsigned int last_drift;
         unsigned long last_jiffies;
         struct timer_list timer;
-        spinlock_t timer_lock;
 };
 
 static struct platform_device *devices[SNDRV_CARDS];
@@ -166,12 +165,12 @@ static inline unsigned int get_rate_shift(struct loopback_pcm *dpcm)
         return get_setup(dpcm)->rate_shift;
 }
 
+/* call in cable->lock */
 static void loopback_timer_start(struct loopback_pcm *dpcm)
 {
         unsigned long tick;
         unsigned int rate_shift = get_rate_shift(dpcm);
 
-        spin_lock(&dpcm->timer_lock);
         if (rate_shift != dpcm->pcm_rate_shift) {
                 dpcm->pcm_rate_shift = rate_shift;
                 dpcm->period_size_frac = frac_pos(dpcm, dpcm->pcm_period_size);
@@ -184,15 +183,13 @@ static void loopback_timer_start(struct loopback_pcm *dpcm)
         tick = (tick + dpcm->pcm_bps - 1) / dpcm->pcm_bps;
         dpcm->timer.expires = jiffies + tick;
         add_timer(&dpcm->timer);
-        spin_unlock(&dpcm->timer_lock);
 }
 
+/* call in cable->lock */
 static inline void loopback_timer_stop(struct loopback_pcm *dpcm)
 {
-        spin_lock(&dpcm->timer_lock);
         del_timer(&dpcm->timer);
         dpcm->timer.expires = 0;
-        spin_unlock(&dpcm->timer_lock);
 }
 
 #define CABLE_VALID_PLAYBACK    (1 << SNDRV_PCM_STREAM_PLAYBACK)
@@ -274,8 +271,8 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
                 spin_lock(&cable->lock);        
                 cable->running |= stream;
                 cable->pause &= ~stream;
-                spin_unlock(&cable->lock);
                 loopback_timer_start(dpcm);
+                spin_unlock(&cable->lock);
                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                         loopback_active_notify(dpcm);
                 break;
@@ -283,23 +280,23 @@ static int loopback_trigger(struct snd_pcm_substream *substream, int cmd)
                 spin_lock(&cable->lock);        
                 cable->running &= ~stream;
                 cable->pause &= ~stream;
-                spin_unlock(&cable->lock);
                 loopback_timer_stop(dpcm);
+                spin_unlock(&cable->lock);
                 if (substream->stream == SNDRV_PCM_STREAM_PLAYBACK)
                         loopback_active_notify(dpcm);
                 break;
         case SNDRV_PCM_TRIGGER_PAUSE_PUSH:
                 spin_lock(&cable->lock);        
                 cable->pause |= stream;
-                spin_unlock(&cable->lock);
                 loopback_timer_stop(dpcm);
+                spin_unlock(&cable->lock);
                 break;
         case SNDRV_PCM_TRIGGER_PAUSE_RELEASE:
                 spin_lock(&cable->lock);
                 dpcm->last_jiffies = jiffies;
                 cable->pause &= ~stream;
-                spin_unlock(&cable->lock);
                 loopback_timer_start(dpcm);
+                spin_unlock(&cable->lock);
                 break;
         default:
                 return -EINVAL;
@@ -477,6 +474,7 @@ static inline void bytepos_finish(struct loopback_pcm *dpcm,
         dpcm->buf_pos %= dpcm->pcm_buffer_size;
 }
 
+/* call in cable->lock */
 static unsigned int loopback_pos_update(struct loopback_cable *cable)
 {
         struct loopback_pcm *dpcm_play =
@@ -485,9 +483,7 @@ static unsigned int loopback_pos_update(struct loopback_cable *cable)
                         cable->streams[SNDRV_PCM_STREAM_CAPTURE];
         unsigned long delta_play = 0, delta_capt = 0;
         unsigned int running, count1, count2;
-        unsigned long flags;
 
-        spin_lock_irqsave(&cable->lock, flags);
         running = cable->running ^ cable->pause;
         if (running & (1 << SNDRV_PCM_STREAM_PLAYBACK)) {
                 delta_play = jiffies - dpcm_play->last_jiffies;
@@ -529,32 +525,39 @@ static unsigned int loopback_pos_update(struct loopback_cable *cable)
         bytepos_finish(dpcm_play, count1);
         bytepos_finish(dpcm_capt, count1);
  unlock:
-        spin_unlock_irqrestore(&cable->lock, flags);
         return running;
 }
 
 static void loopback_timer_function(unsigned long data)
 {
         struct loopback_pcm *dpcm = (struct loopback_pcm *)data;
-        unsigned int running;
+        unsigned long flags;
 
-        running = loopback_pos_update(dpcm->cable);
-        if (running & (1 << dpcm->substream->stream)) {
+        spin_lock_irqsave(&dpcm->cable->lock, flags);
+        if (loopback_pos_update(dpcm->cable) & (1 << dpcm->substream->stream)) {
                 loopback_timer_start(dpcm);
                 if (dpcm->period_update_pending) {
                         dpcm->period_update_pending = 0;
+                        spin_unlock_irqrestore(&dpcm->cable->lock, flags);
+                        /* need to unlock before calling below */
                         snd_pcm_period_elapsed(dpcm->substream);
+                        return;
                 }
         }
+        spin_unlock_irqrestore(&dpcm->cable->lock, flags);
 }
 
 static snd_pcm_uframes_t loopback_pointer(struct snd_pcm_substream *substream)
 {
         struct snd_pcm_runtime *runtime = substream->runtime;
         struct loopback_pcm *dpcm = runtime->private_data;
+        snd_pcm_uframes_t pos;
 
+        spin_lock(&dpcm->cable->lock);
         loopback_pos_update(dpcm->cable);
-        return bytes_to_frames(runtime, dpcm->buf_pos);
+        pos = dpcm->buf_pos;
+        spin_unlock(&dpcm->cable->lock);
+        return bytes_to_frames(runtime, pos);
 }
 
 static struct snd_pcm_hardware loopback_pcm_hardware =
@@ -672,7 +675,6 @@ static int loopback_open(struct snd_pcm_substream *substream)
         dpcm->substream = substream;
         setup_timer(&dpcm->timer, loopback_timer_function,
                     (unsigned long)dpcm);
-        spin_lock_init(&dpcm->timer_lock);
 
         cable = loopback->cables[substream->number][dev];
         if (!cable) {